Breaking change:
VarSetType/VarSetTypeNull classes have been renamed to
SetVarType/SetVarTypeNull
Added phan/phpstan static checkes and settings
Add phpunit tests (in test/phpunit) that are an exact copy from the
trunk folder unit tests
The phan/phpstan tests have been updated to work with the composer layout
config files with static defines needed for certain classes are stored
in test/configs (config.php, config.other.php, config.master.php)
